I. Field of the Invention
The present invention relates generally to bird houses or bird nesting boxes. More particularly, the present invention relates to bird houses that may be changed in form by the user for use by specific bird species. Known prior art is found in United States Class 119, Subclasses 428 and 431.
II. Description of the Prior Art
Numerous wild birds will nest in artificial structures if such bird boxes or bird houses are designed properly. It has long been recognized by those skilled in the art that variations in the size, appearance, dimensions or form of a bird house or nesting box greatly affects the type of bird it attracts. There are several hundred species of birds common to North America, and the nesting habits of various species differ markedly. For a given bird house to be maximally attractive to a particular species, it must have an internal volume in a specific range, and the entrance hole through which birds obtain ingress and egress must be appropriately designed. For optimum attractiveness, the entrance orifice, for example, should be spaced at an attractive height above the bird house floor. Of course the orifice must be sized correctly. It is also important to place birdhouses at an appropriate height above ground that is desired by the target species. By properly configuring a bird house for a given species, it will be much more attractive to members of that species. At the same time, it will be much more unattractive to unwanted species.
I have observed that common North American birds such as wrens, chickadees, downey woodpeckers, nuthatches and titmice prefer a relatively small internal enclosure, usually less than one-hundred cubic inches. Bluebirds, swallows, and many warblers prefer a medium sized nesting volume, of approximately one hundred and fifty cubic inches. Birds such as Ash-throated flycatchers of Great crested flycatchers prefer larger nesting volumes of approximately two-hundred cubic inches or greater. Different species of birds prefer the entrance hole to be at different heights. The optimum entrance hole diameter may vary from one and one-eight inches with chickadees, to one and three-quarters inches with larger flycatchers. With each species the ideal placement height will be different as well.
Thus for a birdwatcher to reliably attract many diverse bird species to his or her yard, numerous bird houses with different dimensions and placements are necessary. For the vendor, who stocks and sells bird houses and bird boxes, the many different required sizes that must be kept in stock makes inventory difficult. For the buyer, the diverse size requirements negatively limit the species of bird that his yard may attract.
U.S. Pat. No. 5,269,255 shows a variable volume bird house. Internal volume may be adjusted by moving a floor panel upwardly or downwardly. Various slots or braces call be used to position the floor at a selected height to make the birdhouse comfortable for specific bird species. However, the wall spacing remains fixed, so that the resultant internal volume may not be shaped like a cube.
U.S. Pat. No. 4,167,917 includes various sliding and removable panels that can vary the entry-hole size for different species of birds,
U.S. Pat. No. 5,746,156 shows the selective sizing of the entry/exit hole by a movable panel.
Other references such as U.S. Pat. Nos. 5,493,997 and 4,442,793 show various common construction details such as folding and sliding panels.
Regardless of size or configuration, bird nesting structures must periodically be maintained and inspected. Old nests should be discarded. The structure must be cleansed of insects or other parasites that may accumulate in tile decomposing organic matter forming the nest. Debris and bird droppings must be removed.
Thus an ideal bird house should be easily broken down or partially disassembled by the user. Additionally, an ideal bird house should have an entrance hole that is optimized In size and location. Floor dimensions and height must also be appropriate for a target species. The structure should exhibit adequate ventilation and drainage characteristics. The roof should be overhanging. Tile enclosure panels should be at least three quarters of an inch thick. Finally, it is best if a perch is omitted.